The Accuracy of Digital Models for Road Design - Geoinformatics for Intelligent Transportation - page 233

The Accuracy of Digital Models for Road
Design

V clav Š af

á ř

and Zden ě k Š mejkal

á

Abstract The paper presents majority of current methods for digital terrain models
(DTM) measuring and basic requirements of traf

c engineers on accuracy in the
process of road design and construction. Conventional geodetic surveying methods
are described as well as modern non-contact methods of the ground surface mea-
surement, e.g. the laser scanning measurements from cars. When designing new
road infrastructure, all the requirements of the environmental impact assessment
imposed by the European Union must be taken into account. In connection with the
application of Directive 2011/92/EU of the European Parliament saying that all
newly constructed multi-lane roads must go through an intense impact on the
environment (EIA analysis) and it also includes repairs of existing roads of more
than 10 km length. Shortest roads may not require an EIA, but still must be built
according to geometrical design standards. Calculations of the horizontal and
vertical road centreline determine the three-dimensional physical location of a road
considering operational, economic and environmental requirements. The density
and accuracy of the DTM determine the final quality and efficiency as the design
work, the quality of the geometric structure of the building. The quality and
accuracy of the DTM especially determine the financial performance of the road

construction. All alternative solutions are then assessed simultaneously with all the
environmental and economic criteria. During reviews variants, for a first approxi-

mation with the situation, can be used DTM with less accuracy approximately
15 cm. For the design selected variant is required the accuracy of DTM around
2

3 cm. Only high quality DTM will allow us to rightly and accurately calculate the
cost of road construction, to determine the exact volume of material moved and
make any necessary animations and simulations. Then all simulations of transport

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